Bieber allegedly became angered when a paparazzo got too close and lost his shoe and hat in the ensuing fight, according to GossipCenter.

Gomez managed to calm Bieber down and he quickly ran to a nearby waiting van to escape the scene. He was followed by Gomez.

A source told the website: "Los Angeles County paramedics arrived at the Calabasas Commons with the Fire Department and Police arriving moments later following Justin's altercation with a paparazzo. Justin's bodyguard [also] arrived while the photographer received medical attention for an apparent strike to the face."

Gomez later posted about the incident on Facebook, writing: "THANKS YOU SO MUCH to my fans for always protecting me and being there for me. I can't thank you guys enough. I'm sorry I had to rush out. Love you guys. (sic)."